[LLVMdev] Troubling promotion of return value to Integer ...

[Evan Cheng]

On Jun 4, 2008, at 11:12 AM, Chris Lattner wrote:

>
> On Jun 4, 2008, at 10:52 AM, Evan Cheng wrote:
>
>>
>> On May 29, 2008, at 10:30 AM, Alireza.Moshtaghi at microchip.com wrote:
>>>
>>>
>>> 4) There will be 4 new function attributes:
>>> sign_ext_from_i8, sign_ext_from_i16
>>> zero_ext_from_i8, zero_ext_from_i16
>>> These attributes will be placed on the function CALL node by
>>> front-end
>>> to inform the backend about such promotions and enable optimization
>>> of
>>> return value. This should be sufficient for direct and indirect
>>> call.
>>> (syntax of these attributes to be defined)
>>
>> Should we go one step further and provide an attribute whose value is
>> the "original type" before the extension?
>
> What would that mean? Can you give an example?

Well, you suggested sext / zext from i8 / i16. Why not from i1 (useful  
for denoting boolean type) or any arbitrary type?

Evan

>
>
> -Chris
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